Sir C. Lyell on the Conical Form of Volcanoes. 221 
others, it is a confused mass distributed over the space occupied 
by the drop. In the latter cuse the indications will not be near- 
ly so good as in the former. 
5. rates, dry, in a number of cases manipulated differently, 
the majority gave no indications, some few gave as ight trace, 
ut in no instance was the indication sufficient. ; 
As the color test is relied upon, perhaps, more than any other 
for medico-legal purposes, it is important to remember that it is 
interfered with by the presence of morphia. When one part by 
_ weight of strychnia is mixed with— 
1. 1 part of morphia, it gives very good results. The colors, 
however, are not so bright as with strychnia alone, 
: 2 Of morphia, in a very small quantity of this mixture the 
Indication of strychnia is very good, in a larger quantity, about 
30 gr., the reaction is just perceptible. ete 
3. 2 of morphia, the indication in a very small quantity is pret- 
ty fair, but in about 7; gr. there is only a mere trace. ate 
- 3 of morphia, in a very small quantity of this mixture, 
the reaction is just perceptible, but in a larger amount there is 
no reaction indicative of the presence of strychnia. 
Columbus, Ohio, July 18, 1859, 
Art. XXV.—On the Consolidation of Lava on Steep Slopes, and 
on the Origin of the Conical Form of Volcanoes ; by Sir CHARLES 
Lyewt, M.A. D.O.L., F.R.S.* 
Durine two recent excursions made in the autumns of 1857 
and 1858 to Mount Etna, Sir C. Lyell had an opportunity of ex- 
amining sections of lava-currents of known date, which had 
escended steep slopes, and had consolidated thereon in tabular 
i inclination of which sometimes exceeded 
This fact has an important bearing on the theory of 
oa 
pnd of lava were often poured out from a . 
central vent. This opinion was a r. Scrope in his 
_ * Proc, Roy. Inst. of Great Britain, April, 1859. 
